[analyzer] Fix hidden node traversal in exploded graph dumps.

The joined nodes now actually have the same state. That was intended
from the start but the original implementation turned out to be buggy.

Differential Revision: https://reviews.llvm.org/D69150

llvm-svn: 375278

Author: haoNoQ

clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

@@ -3030,22 +3030,16 @@ struct DOTGraphTraits<ExplodedGraph*> : public DefaultDOTGraphTraits {
       llvm::function_ref<void(const ExplodedNode *)> PreCallback,
       llvm::function_ref<void(const ExplodedNode *)> PostCallback,
       llvm::function_ref<bool(const ExplodedNode *)> Stop) {
-    const ExplodedNode *FirstHiddenNode = N;
-    while (FirstHiddenNode->pred_size() == 1 &&
-           isNodeHidden(*FirstHiddenNode->pred_begin())) {
-      FirstHiddenNode = *FirstHiddenNode->pred_begin();
-    }
-    const ExplodedNode *OtherNode = FirstHiddenNode;
     while (true) {
-      PreCallback(OtherNode);
-      if (Stop(OtherNode))
+      PreCallback(N);
+      if (Stop(N))
         return true;
 
-      if (OtherNode == N)
+      if (N->succ_size() != 1 || !isNodeHidden(N->getFirstSucc()))
         break;
-      PostCallback(OtherNode);
+      PostCallback(N);
 
-      OtherNode = *OtherNode->succ_begin();
+      N = N->getFirstSucc();
     }
     return false;
   }

clang/test/Analysis/dump_egraph.c

@@ -18,10 +18,30 @@ int foo() {
   return *x + *y;
 }
 
-// CHECK: \"program_points\": [\l    \{ \"kind\": \"Edge\", \"src_id\": 2, \"dst_id\": 1, \"terminator\": null, \"term_kind\": null, \"tag\": null, \"node_id\": 1, \"is_sink\": 0, \"has_report\": 0 \}\l  ],\l  \"program_state\": null
-
-// CHECK: \"program_points\": [\l    \{ \"kind\": \"BlockEntrance\", \"block_id\": 1
-
+// CHECK: \"program_points\": [\l
+// CHECK-SAME: \{ \"kind\": \"Edge\", \"src_id\": 2, \"dst_id\": 1,
+// CHECK-SAME:    \"terminator\": null, \"term_kind\": null, \"tag\": null,
+// CHECK-SAME:    \"node_id\": 1, \"is_sink\": 0, \"has_report\": 0
+// CHECK-SAME: \},
+// CHECK-SAME: \{ \"kind\": \"BlockEntrance\", \"block_id\": 1, \"tag\": null,
+// CHECK-SAME:    \"node_id\": 2, \"is_sink\": 0, \"has_report\": 0
+// CHECK-SAME: \},
+// CHECK-SAME: \{ \"kind\": \"Statement\", \"stmt_kind\": \"IntegerLiteral\",
+// CHECK-SAME:    \"stmt_id\": 597, \"pointer\": \"0x{{[0-9a-f]*}}\",
+// CHECK-SAME:    \"pretty\": \"0\", \"location\": \{
+// CHECK-SAME:        \"line\": 15, \"column\": 12, \"file\":
+// CHECK-SAME:    \}, \"stmt_point_kind\": \"PreStmtPurgeDeadSymbols\",
+// CHECK-SAME:    \"tag\": \"ExprEngine : Clean Node\", \"node_id\": 3,
+// CHECK-SAME:    \"is_sink\": 0, \"has_report\": 0
+// CHECK-SAME: \},
+// CHECK-SAME: \{ \"kind\": \"Statement\", \"stmt_kind\": \"IntegerLiteral\",
+// CHECK-SAME:    \"stmt_id\": 597, \"pointer\": \"0x{{[0-9a-f]*}}\",
+// CHECK-SAME:    \"pretty\": \"0\", \"location\": \{
+// CHECK-SAME:        \"line\": 15, \"column\": 12, \"file\":
+// CHECK-SAME:    \}, \"stmt_point_kind\": \"PostStmt\", \"tag\": null,
+// CHECK-SAME:    \"node_id\": 4, \"is_sink\": 0, \"has_report\": 0
+// CHECK-SAME: \}
+// CHECK-SAME: ]
 
 // CHECK: \"pretty\": \"*x\", \"location\": \{ \"line\": 18, \"column\": 10, \"file\": \"{{(.+)}}dump_egraph.c\" \}